acpi: fix potential call to a freed memory section.

Strip __cpuinit[data] from Node <-> PXM routines and supporting data
structures.  Also make pxm_to_node_map and node_to_pxm_map local to the
numa acpi module.

This fixes a bug triggered by the following conditions:
- boot on a machine with a SLIT table defined
- kernel is configured w/ CONFIG_HOTPLUG_CPU=n
- cat /sys/devices/system/node/node*/distance
This will cause an oops by calling into a freed memory section.

In particular, on x86_64, __node_distance calls node_to_pxm().

Signed-off-by: Aaron Durbin <adurbin@google.com>
Cc: Len Brown <lenb@kernel.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/acpi/numa.c

@@ -40,19 +40,19 @@ static nodemask_t nodes_found_map = NODE_MASK_NONE;
 #define NID_INVAL	-1
 
 /* maps to convert between proximity domain and logical node ID */
-int __cpuinitdata pxm_to_node_map[MAX_PXM_DOMAINS]
+static int pxm_to_node_map[MAX_PXM_DOMAINS]
 				= { [0 ... MAX_PXM_DOMAINS - 1] = NID_INVAL };
-int __cpuinitdata node_to_pxm_map[MAX_NUMNODES]
+static int node_to_pxm_map[MAX_NUMNODES]
 				= { [0 ... MAX_NUMNODES - 1] = PXM_INVAL };
 
-int __cpuinit pxm_to_node(int pxm)
+int pxm_to_node(int pxm)
 {
 	if (pxm < 0)
 		return NID_INVAL;
 	return pxm_to_node_map[pxm];
 }
 
-int __cpuinit node_to_pxm(int node)
+int node_to_pxm(int node)
 {
 	if (node < 0)
 		return PXM_INVAL;

include/acpi/acpi_numa.h

@@ -11,11 +11,8 @@
 #define MAX_PXM_DOMAINS (256)	/* Old pxm spec is defined 8 bit */
 #endif
 
-extern int __cpuinitdata pxm_to_node_map[MAX_PXM_DOMAINS];
-extern int __cpuinitdata node_to_pxm_map[MAX_NUMNODES];
-
-extern int __cpuinit pxm_to_node(int);
-extern int __cpuinit node_to_pxm(int);
+extern int pxm_to_node(int);
+extern int node_to_pxm(int);
 extern int __cpuinit acpi_map_pxm_to_node(int);
 extern void __cpuinit acpi_unmap_pxm_to_node(int);